Department of Materials Science and Engineering, Texas A&M University, College Station, TX 77843-3123, USA.
School of Materials Engineering, Purdue University, West Lafayette, IN 47907, USA.
Sci Rep. 2017 Jan 3;7:39484. doi: 10.1038/srep39484.
High energy particle radiations induce severe microstructural damage in metallic materials. Nanoporous materials with a giant surface-to-volume ratio may alleviate radiation damage in irradiated metallic materials as free surface are defect sinks. Here we show, by using in situ Kr ion irradiation in a transmission electron microscope at room temperature, that nanoporous Au indeed has significantly improved radiation tolerance comparing with coarse-grained, fully dense Au. In situ studies show that nanopores can absorb and eliminate a large number of radiation-induced defect clusters. Meanwhile, nanopores shrink (self-heal) during radiation, and their shrinkage rate is pore size dependent. Furthermore, the in situ studies show dose-rate-dependent diffusivity of defect clusters. This study sheds light on the design of radiation-tolerant nanoporous metallic materials for advanced nuclear reactor applications.
高能粒子辐射会在金属材料中引起严重的微观结构损伤。具有巨大比表面积的纳米多孔材料可以减轻辐照金属材料中的辐射损伤，因为自由表面是缺陷的汇。在这里，我们通过在室温下使用透射电子显微镜中的原位 Kr 离子辐照，表明纳米多孔 Au 确实比粗晶、完全致密的 Au 具有显著提高的辐射耐受性。原位研究表明，纳米孔可以吸收和消除大量的辐射诱导缺陷团簇。同时，纳米孔在辐照过程中收缩（自愈合），并且其收缩率与孔径有关。此外，原位研究表明缺陷团簇的扩散率随剂量率而变化。这项研究为先进核反应堆应用中辐射耐受纳米多孔金属材料的设计提供了思路。
